Timeline for Is there a universal countable group? (a countable group containing every countable group as a subgroup)
Current License: CC BY-SA 2.5
5 events
| when toggle format | what | by | license | comment | |
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| Jun 22, 2010 at 16:01 | comment | added | Péter Komjáth | Yes, Joel, that's what I meant. Thank you. | |
| Jun 22, 2010 at 16:00 | history | edited | Péter Komjáth | CC BY-SA 2.5 |
adding the missing word universal
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| Jun 22, 2010 at 13:35 | comment | added | Simon Thomas | Any countable abelian group can be embedded in a divisible countable abelian group. So you obtain a universal countable abelian groups by taking a direct sum of countably many copies of $\mathbb{Q}$ and $\mathbb{Z}[p^{\infty}]$ for each prime $p$. | |
| Jun 22, 2010 at 13:08 | comment | added | Joel David Hamkins | Peter, I guess you mean a universal countable abelian group. But could you explain a bit more? | |
| Jun 22, 2010 at 3:53 | history | answered | Péter Komjáth | CC BY-SA 2.5 |